US 12,262,574 B2
Light-emitting element
Satoshi Seo, Kanagawa (JP); Hiromi Seo, Kanagawa (JP); and Tatsuyoshi Takahashi, Kanagawa (JP)
Assigned to Semiconductor Energy Laboratory Co., Ltd., Atsugi (JP)
Filed by SEMICONDUCTOR ENERGY LABORATORY CO., LTD., Atsugi (JP)
Filed on Aug. 11, 2023, as Appl. No. 18/232,861.
Application 18/232,861 is a continuation of application No. 17/829,498, filed on Jun. 1, 2022, granted, now 11,730,007.
Application 17/829,498 is a continuation of application No. 16/944,257, filed on Jul. 31, 2020, granted, now 11,355,722, issued on Jun. 7, 2022.
Application 16/944,257 is a continuation of application No. 16/412,529, filed on May 15, 2019, granted, now 10,734,594, issued on Aug. 4, 2020.
Application 16/412,529 is a continuation of application No. 15/946,094, filed on Apr. 5, 2018, granted, now 10,644,254, issued on May 5, 2020.
Application 15/946,094 is a continuation of application No. 15/412,515, filed on Jan. 23, 2017, granted, now 9,947,885, issued on Apr. 17, 2018.
Application 15/412,515 is a continuation of application No. 15/051,910, filed on Feb. 24, 2016, granted, now 9,559,313, issued on Jan. 31, 2017.
Application 15/051,910 is a continuation of application No. 13/957,612, filed on Aug. 2, 2013, granted, now 9,276,228, issued on Mar. 1, 2016.
Claims priority of application No. 2012-172830 (JP), filed on Aug. 3, 2012.
Prior Publication US 2024/0049493 A1, Feb. 8, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. H10K 50/11 (2023.01); C09K 11/02 (2006.01); C09K 11/06 (2006.01); H10K 50/15 (2023.01); H10K 50/16 (2023.01); H10K 85/30 (2023.01); H10K 85/60 (2023.01); H10K 101/10 (2023.01); H10K 101/30 (2023.01); H10K 101/40 (2023.01)
CPC H10K 50/11 (2023.02) [C09K 11/02 (2013.01); C09K 11/06 (2013.01); H10K 50/15 (2023.02); H10K 50/16 (2023.02); H10K 85/321 (2023.02); H10K 85/611 (2023.02); H10K 85/622 (2023.02); H10K 85/633 (2023.02); H10K 85/636 (2023.02); H10K 85/6572 (2023.02); H10K 85/6576 (2023.02); C09K 2211/1007 (2013.01); C09K 2211/1011 (2013.01); C09K 2211/1014 (2013.01); C09K 2211/1029 (2013.01); C09K 2211/1044 (2013.01); C09K 2211/1092 (2013.01); H10K 85/615 (2023.02); H10K 85/624 (2023.02); H10K 85/654 (2023.02); H10K 2101/10 (2023.02); H10K 2101/30 (2023.02); H10K 2101/40 (2023.02)] 19 Claims
OG exemplary drawing
 
1. A light-emitting element comprising:
a light-emitting layer between a pair of electrodes,
wherein the light-emitting layer comprises a thermally activated delayed fluorescent substance and a material which emits fluorescence, the thermally activated delayed fluorescent substance generating a singlet excited state from a triplet excited state by reverse intersystem crossing,
wherein the thermally activated delayed fluorescent substance comprises a x-electron rich heteroaromatic ring,
wherein a level of the singlet excited state generated by the thermally activated delayed fluorescent substance is higher than a level of a singlet excited state of the material which emits fluorescence, and
wherein an emission spectrum of the thermally activated delayed fluorescent substance overlaps with an absorption band on the longest wavelength side in an absorption spectrum of the material which emits fluorescence.